3D modelling of thermal loads during unmitigated vertical displacement events in ITER and JET

TL;DR

This paper introduces a physics-based workflow for predicting 3D thermal loads during tokamak disruptions, validated on JET and applied to ITER conditions to assess wall resilience.

Contribution

A novel integrated simulation approach coupling MHD, field line tracing, and thermal response for accurate disruption heat load predictions in fusion devices.

Findings

Validated workflow reproduces JET disruption dynamics and melting phenomena.

Predicts ITER tungsten wall resilience and energy deposition during disruptions.

Enables scenario-specific thermal load assessments for future fusion devices.

Abstract

Predicting three-dimensional thermal loads during tokamak disruptions is essential for ITER yet remains weakly developed. We present a physics-based workflow that couples MHD simulations of vertical displacement events with field line tracing on a realistic 3D first wall model and a transient wall thermal response. The approach is validated against JET discharges with beryllium main chamber armour, reproducing key global dynamics, non-axisymmetric current features, and the occurrence (or absence) of melting, thereby building confidence in the methodology. We then apply the same workflow to ITER-relevant conditions with tungsten (W) armour, consistent with the new 2024 ITER re-baseline, to assess disruption heat loads and their 3D localization. The resulting analysis demonstrates the resilience of the ITER W first wall against these events and provides predictions for the energy deposition and current flow profiles. Beyond these studies, the workflow enables scenario-by-scenario estimates of disruption-induced thermal loading, allowing to assess the disruption-budget consumption for these events in future devices.